JP2502291B2 - How to stop the tape - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for stopping a tape-shaped body, and more particularly to a method for stopping the tape-shaped body when the end of the tape-shaped body wound between a pair of reels is detected. It relates to a method for transitioning a body from being transported at high speed to a stopped state.

[Conventional technology]

There is a well-known video tape recorder (VTR) as a device for stopping the tape-shaped body as described above, and this VTR will be described below as an example.

FIG. 4 is a diagram showing the structure of a general VTR. 1 in the figure
Is a cassette, 2 is a supply reel, 3 is a take-up reel, 4 is a magnetic tape, and the magnetic tape 4 is both reels in the cassette 1.
It is wrapped in a few. When the magnetic tape 4 is housed in the cassette 1, the tape 4 is stretched between the guide pins 17a and 17b in the cassette 1 so as to be exposed at the opening 1a of the cassette.

This stretched magnetic tape 4 (shown by dotted lines in FIG. 4) is moved to the opening 1 at the moving guide posts 6, 7, 8 and 9.
By pulling out from a and winding the rotary head around the cylinder 5 provided on the peripheral surface thereof, the recording / reproducing on the tape 4 becomes possible. At this time, when the so-called tape loading is completed, the tape path is the above-mentioned moving guide posts 6, 7, 8,
Fixed guide post 1 that was previously fixed to the device body together with 9
It is determined by 2,13,14.

A loading ring 15 is rotatably held along a guide member (not shown), and moving guide posts 6, 7, 8 are planted on the loading ring 15.

Further, in the drawing, 11 is a captan for conveying the tape 4 along the tape path, and 10 is a pinch roller which is pressed against the capstan 11. The pinch roller 10 is set up on the rotatable lever 16 together with the moving guide post 9, and the lever 16 is moved from the inside of the opening 1a to the position shown in the figure by a mechanism (not shown).

By the way, in the above-mentioned VTR, the tape is automatically stopped when the end of the tape is reached in the so-called fast-forwarding and rewinding state of the tape. The method of detecting the end of the tape includes a method of detecting the rotation stop of the reel and a method of detecting the transparent portion provided at the end of the tape, but the former is after the tape is completely wound on one reel. Also, the latter is usually adopted because the reel is driven and a large load is applied to the tape.

[Problems to be solved by the invention]

However, in the case where the end is detected by the latter method, even if the voltage applied to the reel driving motor is set to 0, the rotation of the reel does not stop immediately due to the inertia of the motor and the reel, so that the tape may end up on one side. The rotation of the reel continued until it was completely wound up on the reel, which sometimes gave a large load to the tape.

In view of the above-mentioned problems, the present invention provides a method for stopping a tape-shaped body that can stop the tape-shaped body at a desired position without applying a load to the tape-shaped body after the end of the tape-shaped body is detected. The purpose is to do.

[Means for solving problems]

To this end, according to the present invention, in a device provided with a transmission mechanism for selectively transmitting the driving force of the motor to a pair of reels around which the tape-shaped body is wound according to the rotation direction of the motor. A method of shifting from the state in which the tape-shaped body is being conveyed at a high speed to the stopped state when the end of the tape-shaped body is detected. The rotation direction of the motor is reversed, the reel to which the driving force is transmitted by the transmission mechanism is switched, the tape-shaped body is made to run in a direction opposite to that before the end detection, and then the motor is rotated again. The pair of reels is controlled to reverse the direction and run the tape-shaped body at a low speed in the same direction as before the end detection, and stop the tape-shaped body when the end is detected again. Was Unishi.

[Action]

According to the method described above, the drive force transmission path of the motor is instantaneously cut off from the reel being driven during high-speed transport of the tape-shaped body, so that the tape-shaped body is completely wound on one reel. There is no. Further, when the second end is detected, since the inertia of the motor is small, the tape-shaped body can be reliably stopped at the desired stop position.

〔Example〕

The tape drive control unit of the VTR as one embodiment of the present invention will be described below. The configuration of the other parts is the same as that of FIG. 4, and the description thereof is omitted.

FIG. 2 is a diagram for explaining the tape drive control section of the VTR of this embodiment, and FIG. 3 is a side view of the reel drive mechanism in FIG. In the figure, 21 is a take-up reel stand, 22 is a take-up reel stand
21 is a gear meshing with the gear, 23 is a supply reel base, and 24 is a gear meshing with the gear of the supply reel base 22.

On the other hand, 26 is a capstan motor for driving the capstan 11 in FIG. 4, 27 is a belt 25 for transmitting the driving force of the capstan motor 26, and a belt 22 is a gear 22 in accordance with the rotation direction of the capstan motor 26. , 24, is a gear unit that selectively transmits a driving force to the gear 25a, which is a gear 25a rotated by a belt 27, a lever 25b rotatable about a rotation axis of the gear 25a, and a lever 25b. It is composed of a gear 25c that rotates around its rotating end and can mesh with the gears 22 and 24.

When the capstan motor 26 is rotating in the direction A in the figure, the gear unit 25 swings the lever 25b toward the take-up reel side, rolls the gear 25a to the gear 22, and transmits the driving force to the take-up reel stand 21. To do. On the other hand, when the capstan motor 26 is rotating in the B direction in the figure, the driving force is similarly transmitted to the supply reel base 23.

28 is a motor control circuit for controlling the voltage applied to the capstan motor 26, 29 is a system controller, 30 is a well-known tape end detector, and 31 and 32 are brakes for braking the reel stands 21 and 23, respectively. is there. As is well known, the tape end detector 30 uses a light receiving element and a light emitting element to detect a transparent portion at the end of the tape, and a detailed description thereof will be omitted here.

FIG. 1 is a timing chart for explaining the operation of the tape drive control unit in FIG. 2, and the operation accompanying the detection of the end of the tape when the tape is being conveyed at high speed will be described below with reference to FIG. Will be explained.

Now, assume that the drive voltage V is applied to the capstan motor 26, the motor 26 rotates in the direction A in FIG. 2, and the take-up reel stand 21 rotates at high speed to convey the tape at high speed. . At this time, when the end of the tape is detected by the end detector 30 (timing shown in t ₁ in FIG. ₁ ), the system controller 29 causes the motor control circuit 28 to drive the motor 26 with a driving voltage −
Apply V. Along with this, the motor 26 rotates in the direction indicated by B in FIG. 2, and the gear 25c separates from the gear 22 and the gear 24c.
Be transferred to.

Therefore, the transmission of power between the reel base 21 and the motor 26 is instantaneously cut off, so that the winding rill base 21 does not continue to rotate due to the inertia of the motor 26 and its driving force transmission mechanism. The load is applied to the table 21 in advance, so that the table 21 stops instantly.

Until the gear 25c is separated from the gear 22 and is rollingly contacted with the gear 24, neither of the reel bases 21 and 23 receives the driving force from the motor 26, so both reel bases 21 and 23 are stopped during this period. Become. However, due to the tape tension or the like, the stop timing of the supply reel base 23 is slightly delayed as compared with the stop timing of the take-up reel base 21, and the tape sags.

Therefore, by applying a driving voltage -V for a predetermined period T (shown in FIG. 1) to the end detector motor 26, the gear 25c is brought into rolling contact with the gear 24 to rotate the supply reel base 23, and the tape is supplied to the supply reel side. To wind up. Then, after that, a voltage for rotating the motor 26 again in the A direction at a low speed is applied to the motor 26 so that the gear 25c is brought into rolling contact with the gear 22 and the tape is run to the take-up reel side.

After that, when the end detector 30 detects the end again (first
At a timing indicated by t ₂ in the drawing), the applied voltage to the motor 26 is set to 0, and the brakes 32 and 31 are brought into contact with the brake shoes provided on the reel stands 21 and 23 to stop the tape running. At this time, since the inertia of the motor 26 is small, the take-up reel stand 21 does not continue to rotate until the tape is completely taken up by the take-up reel.

As described above, in the VTR of this embodiment, when the tape is stopped from the high-speed running state when the tape end is detected, the tape is completely wound on the reel and a large load is applied to the tape. In addition, the tape can be stopped at a desired position (a position immediately after the end is detected) without causing slack in the tape.

In the above description, the motor 26 is also used as a capstan motor, but the pinch roller is separated from the capstan when the tape is conveyed at high speed, and the tape is conveyed by the capstan. Not to mention not. Further, the motor 26 may be a reel-only motor.

Further, in the above description, the case where the tape is wound on the take-up reel side and reaches the end is described, but the motor 26 is similarly controlled when the tape is wound on the supply reel side and reaches the end. As a result, the same effect can be obtained.

〔The invention's effect〕

As described above, according to the present invention, when the tape-shaped body is stopped at the end of the tape-shaped body when the tape-shaped body is conveyed at a high speed, the tape-shaped body is stopped. It is possible to stop the tape-shaped body between both reels without sagging at a desired position without applying a large load.

[Brief description of drawings]

FIG. 1 is a timing chart for explaining the operation of a tape drive control unit of a VTR as an embodiment of the present invention, and FIG. 2 is a diagram showing a tape drive control unit of a VTR as an embodiment of the present invention. FIG. 3 is a side view of the reel drive mechanism shown in FIG. 2, and FIG. 4 is a view showing the structure of a general VTR. In the figure, 21 is a take-up reel, 23 is a supply reel, 25 is a switching gear unit, 26 is a motor, 28 is a motor control circuit, 29 is a system controller, 30 is an end detector, and 31 and 32 are brakes.

Claims (1)

(57) [Claims] 1. An apparatus provided with a transmission mechanism for selectively transmitting a driving force of a motor to a pair of reels around which a tape-shaped body is wound according to a rotation direction of the motor,
A method of shifting from a state in which the tape-shaped body is conveyed at a high speed to a stopped state when the end of the tape-shaped body is detected. The rotation direction of the motor is reversed, the reels to which the driving force is transmitted by the transmission mechanism are switched, the tape-shaped body is made to run in the direction opposite to that before the end detection, and then the rotation direction of the motor is made again. And the pair of reels are controlled to stop the tape-shaped body in response to the detection of the end again. How to stop the tape.